Wiring board and method of fabricating the same

Abstract

A wiring board includes an electrode pad having a first surface and a second surface located on an opposite side from the first surface, a conductor pattern connected to the first surface of the electrode pad, and an insulator layer embedded with the electrode pad and the conductor pattern. The insulator layer covers an outer peripheral portion of the second surface of the electrode pad.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of a Japanese Patent Application No. 2008-259016 filed on Oct. 3, 2008, in the Japanese Patent Office, the disclosure of which is hereby incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a wiring board having electrode pads, conductor patterns connected to the electrode pads and an insulator layer embedded with the electrodes and the conductor patterns, and to a method of fabricating such a wiring board.[0004]2. Description of the Related Art[0005]Wiring boards having various shapes and structures have been proposed for use in mounting thereon electronic components such as semiconductor chips. Recently, there are increased demands to reduce the thickness and size of the wiring board mounted with the semiconductor chip, due to the reduced thickness and size of the semiconductor chip.[0006]Known methods of forming thin wiring boards ...

AI Technical Summary

Benefits of technology

The present invention provides a novel and useful wiring board and method of fabricating the same, which solves the problem of delamination between the electrode pad and insulator layer. The wiring board has an electrode pad with a conductor pattern embedded in an insulator layer covering the outer peripheral portion of the electrode pad. The method includes steps of forming the electrode pad on a support plate, etching the support plate to form a projecting part, and then forming the insulator layer covering the electrode pad and the projecting part. The conductor pattern is then formed on the insulator layer, and the support plate is removed to expose a portion of the electrode pad. The invention provides a reliable wiring board with improved delamination suppression.

Problems solved by technology

However, the thickness of the core substrate, which forms the base for the wiring board, interferes with the further reduction in the thickness of the wiring board that is fabricated using the build-up method.

However, when the shape of the electrode pad is complex as in the case of this proposed electrode pad structure, the number of processes required to form the electrode pad increases, to thereby increase the fabrication cost of the wiring board.

However, according to this proposed structure, the delamination at the boundary surface between the electrode pad and the insulator layer cannot be suppressed satisfactorily, and it is difficult to prevent the reliability of the wiring board from deteriorating due to the delamination.

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